Method of manufacturing a CMOS image sensor

Abstract

A complementary metal oxide silicon (CMOS) image sensor includes a pad protection layer having a dual-layer structure including a plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) layer as a lower layer and a thermo-setting resin layer as an upper layer. The thermo-setting resin layer is removed before a micro-lens process and after a planarization process. The plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) layer is removed after the planarization process and the micro-lens process.

1. A method for manufacturing a complementary metal oxide silicon (CMOS) image sensor comprising:
 depositing an oxide layer and a nitride layer after forming a pad over a substrate; 
 exposing the pad by etching the oxide layer and the nitride layer; 
 depositing a plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) layer as a pad protection layer, and depositing a thermo-setting resin layer over the PE-TEOS layer; 
 forming a color filter array; 
 forming a planarization layer over the color filter array; 
 removing the thermo-setting resin layer in a pad area; 
 forming a micro-lens over the planarization layer; and 
 exposing the pad by removing the plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) layer in the pad area; 
 wherein thickness of the thermo-setting resin layer is in the range of about 200 Å to about 600 Å. 
 
   
   
     2. The method as claimed in  claim 1 , wherein thickness of the plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) layer is in the range of about 200 Å about 500 Å. 
   
   
     3. The method as claimed in  claim 1 , wherein the thermo-setting resin layer is removed through oxygen ashing. 
   
   
     4. The method as claimed in  claim 3 , wherein an oxygen ashing process is targeted to remove a thermo-setting resin layer between twice to triple the thickness of the thermo-setting resin layer actually deposited over the PE-TEOS layer. 
   
   
     5. The method as claimed in  claim 3 , wherein the plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) layer is removed through dry etch. 
   
   
     6. The method as claimed in  claim 1 , wherein an initial thickness of the deposited planarization layer is about 10,000 Å. 
   
   
     7. The method as claimed in  claim 1 , wherein the thermo-setting resin layer and the color filter array both comprise photoresist.